Bug 1248486 (CVE-2015-4177)

Summary:	CVE-2015-4177 kernel: Race conditions in collect_mounts
Product:	[Other] Security Response	Reporter:	Wade Mealing <wmealing>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	agordeev, aquini, arm-mgr, bhu, dhoward, fhrbata, gansalmon, itamar, jkacur, joelsmith, jonathan, jrusnack, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, mchehab, mguzik, nmurray, plougher, pmatouse, rt-maint, rvrbovsk, slawomir, slong, vgoyal, vkaigoro, vkrizan, williams, wmealing
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A flaw was discovered in the kernel's collect_mounts function. If the kernel's audit subsystem called collect_mounts to audit an unmounted path, it could panic the system. With this flaw, an unprivileged user could call umount(MNT_DETACH) to launch a denial-of-service attack.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-08-25 12:28:16 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1224245

Description Wade Mealing 2015-07-30 11:46:36 UTC

The audit subsystem can call collect_mounts, which if attempting to audit
a mountpoint which is no longer mounted can panic the system.

Upstream patch:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cd4a40174b71acd021877341684d8bb1dc8ea4ae

CVE Request:
http://seclists.org/oss-sec/2015/q2/640

Comment 4 Wade Mealing 2015-08-20 03:51:34 UTC

Statement:

This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 5, 6, MRG-2, realtime and arm-kernels.

The issue is not currently planned to be addressed in Red Hat Enterprise Linux 7.